Inbred corn line LH185Bt810

ABSTRACT

An inbred corn line, designated LH185Bt810, is disclosed. The invention relates to the seeds of inbred corn line LH185Bt810, to the plants of inbred corn line LH185Bt810 and to methods for producing a corn plant produced by crossing the inbred line LH185Bt810 with itself or another corn line. The invention further relates to hybrid corn seeds and plants produced by crossing the inbred line LH185Bt810 with another corn line.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinctive corn inbred line,designated LH185Bt810. There are numerous steps in the development ofany novel, desirable plant germplasm. Plant breeding begins with theanalysis and definition of problems and weaknesses of the currentgermplasm, the establishment of program goals, and the definition ofspecific breeding objectives. The next step is selection of germplasmthat possess the traits to meet the program goals. The goal is tocombine in a single variety or hybrid an improved combination ofdesirable traits from the parental germplasm. These important traits mayinclude higher yield, resistance to diseases and insects, better stalksand roots, tolerance to drought and heat, and better agronomic quality.

Choice of breeding or selection methods depends on the mode of plantreproduction, the heritability of the trait(s) being improved, and thetype of cultivar used commercially (e.g., F₁ hybrid cultivar, purelinecultivar, etc.). For highly heritable traits, a choice of superiorindividual plants evaluated at a single location will be effective,whereas for traits with low heritability, selection should be based onmean values obtained from replicated evaluations of families of relatedplants. Popular selection methods commonly include pedigree selection,modified pedigree selection, mass selection, and recurrent selection.

The complexity of inheritance influences choice of the breeding method.Backcross breeding is used to transfer one or a few favorable genes fora highly heritable trait into a desirable cultivar. This approach hasbeen used extensively for breeding disease-resistant cultivars. Variousrecurrent selection techniques are used to improve quantitativelyinherited traits controlled by numerous genes. The use of recurrentselection in self-pollinating crops depends on the ease of pollination,the frequency of successful hybrids from each pollination, and thenumber of hybrid offspring from each successful cross.

Each breeding program should include a periodic, objective evaluation ofthe efficiency of the breeding procedure. Evaluation criteria varydepending on the goal and objectives, but should include gain fromselection per year based on comparisons to an appropriate standard,overall value of the advanced breeding lines, and number of successfulcultivars produced per unit of input (e.g., per year, per dollarexpended, etc.).

Promising advanced breeding lines are thoroughly tested and compared toappropriate standards in environments representative of the commercialtarget area(s) for three years at least. The best lines are candidatesfor new commercial cultivars; those still deficient in a few traits areused as parents to produce new populations for further selection.

These processes, which lead to the final step of marketing anddistribution, usually take from eight to 12 years from the time thefirst cross is made. Therefore, development of new cultivars is atime-consuming process that requires precise forward planning, efficientuse of resources, and a minimum of changes in direction.

A most difficult task is the identification of individuals that aregenetically superior, because for most traits the true genotypic valueis masked by other confounding plant traits or environmental factors.One method of identifying a superior plant is to observe its performancerelative to other experimental plants and to a widely grown standardcultivar. If a single observation is inconclusive, replicatedobservations provide a better estimate of its genetic worth.

The goal of plant breeding is to develop new, unique and superior corninbred lines and hybrids. The breeder initially selects and crosses twoor more parental lines, followed by repeated selfing and selection,producing many new genetic combinations. The breeder can theoreticallygenerate billions of different genetic combinations via crossing,selfing and mutations. The breeder has no direct control at the cellularlevel. Therefore, two breeders will never develop the same line, or evenvery similar lines, having the same corn traits.

Each year, the plant breeder selects the germplasm to advance to thenext generation. This germplasm is grown under unique and differentgeographical, climatic and soil conditions, and further selections arethen made, during and at the end of the growing season. The inbred lineswhich are developed are unpredictable. This unpredictability is becausethe breeder's selection occurs in unique environments, with no controlat the DNA level (using conventional breeding procedures), and withmillions of different possible genetic combinations being generated. Abreeder of ordinary skill in the art cannot predict the final resultinglines he develops, except possibly in a very gross and general fashion.The same breeder cannot produce the same line twice by using the exactsame original parents and the same selection techniques. Thisunpredictability results in the expenditure of large research monies todevelop a superior new corn inbred line.

The development of commercial corn hybrids requires the development ofhomozygous inbred lines, the crossing of these lines, and the evaluationof the crosses. Pedigree breeding and recurrent selection breedingmethods are used to develop inbred lines from breeding populations.Breeding programs combine desirable traits from two or more inbred linesor various broad-based sources into breeding pools from which inbredlines are developed by selfing and selection of desired phenotypes. Thenew inbreds are crossed with other inbred lines and the hybrids fromthese crosses are evaluated to determine which have commercialpotential.

Pedigree breeding is used commonly for the improvement ofself-pollinating crops or inbred lines of cross-pollinating crops. Twoparents which possess favorable, complementary traits are crossed toproduce an F₁. An F₂ population is produced by selfing one or severalF₁'s or by intercrossing two F₁'s (sib mating). Selection of the bestindividuals is usually begun in the F₂ population; then, beginning inthe F₃, the best individuals in the best families are selected.Replicated testing of families, or hybrid combinations involvingindividuals of these families, often follows in the F₄ generation toimprove the effectiveness of selection for traits with low heritability.At an advanced stage of inbreeding (i.e., F₆ and F₇), the best lines ormixtures of phenotypically similar lines are tested for potentialrelease as new cultivars.

Mass and recurrent selections can be used to improve populations ofeither self- or cross-pollinating crops. A genetically variablepopulation of heterozygous individuals is either identified or createdby intercrossing several different parents. The best plants are selectedbased on individual superiority, outstanding progeny, or excellentcombining ability. The selected plants are intercrossed to produce a newpopulation in which further cycles of selection are continued.

Backcross breeding has been used to transfer genes for a simplyinherited, highly heritable trait into a desirable homozygous cultivaror inbred line which is the recurrent parent. The source of the trait tobe transferred is called the donor parent. The resulting plant isexpected to have the attributes of the recurrent parent (e.g., cultivar)and the desirable trait transferred from the donor parent. After theinitial cross, individuals possessing the phenotype of the donor parentare selected and repeatedly crossed (backcrossed) to the recurrentparent. The resulting plant is expected to have the attributes of therecurrent parent (e.g., cultivar) and the desirable trait transferredfrom the donor parent.

Descriptions of other breeding methods that are commonly used fordifferent traits and crops can be found in one of several referencebooks (e.g., Allard, 1960; Simmonds, 1979; Sneep et al., 1979; Fehr,1987).

Proper testing should detect any major faults and establish the level ofsuperiority or improvement over current cultivars. In addition toshowing superior performance, there must be a demand for a new cultivarthat is compatible with industry standards or which creates a newmarket. The introduction of a new cultivar will incur additional coststo the seed producer, the grower, processor and consumer; for specialadvertising and marketing, altered seed and commercial productionpractices, and new product utilization. The testing preceding release ofa new cultivar should take into consideration research and developmentcosts as well as technical superiority of the final cultivar. Forseed-propagated cultivars, it must be feasible to produce seed easilyand economically.

Once the inbreds that give the best hybrid performance have beenidentified, the hybrid seed can be reproduced indefinitely as long asthe homogeneity of the inbred parent is maintained. A single-crosshybrid is produced when two inbred lines are crossed to produce the F₁progeny. A double-cross hybrid is produced from four inbred linescrossed in pairs (A×B and C×D) and then the two F₁ hybrids are crossedagain (A×B)×(C×D). Much of the hybrid vigor exhibited by F₁ hybrids islost in the next generation (F₂). Consequently, seed from hybridvarieties is not used for planting stock.

Corn is an important and valuable field crop. Thus, a continuing goal ofplant breeders is to develop stable, high yielding corn hybrids that areagronomically sound. The reasons for this goal are obviously to maximizethe amount of grain produced on the land used and to supply food forboth animals and humans. To accomplish this goal, the corn breeder mustselect and develop corn plants that have the traits that result insuperior parental lines for producing hybrids.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred corn line,designated LH185Bt810. This invention thus relates to the seeds ofinbred corn line LH185Bt810, to the plants of inbred corn lineLH185Bt810 and to methods for producing a corn plant produced bycrossing the inbred line LH185Bt810 with itself or another corn line.This invention further relates to hybrid corn seeds and plants producedby crossing the inbred line LH185Bt810 with another corn line.

The inbred corn plant of the invention may further comprise, or have, acytoplasmic factor that is capable of conferring male sterility. Partsof the corn plant of the present invention are also provided, such ase.g., pollen obtained from an inbred plant and an ovule of the inbredplant.

In one aspect, the present invention provides for single gene convertedplants of LH185Bt810. The single transferred gene may preferably be adominant or recessive allele. Preferably, the single transferred genewill confer such traits as male sterility, herbicide resistance, insectresistance, resistance for bacterial, fungal, or viral disease, malefertility, enhanced nutritional quality, and industrial usage. Thesingle gene may be a naturally occurring maize gene or a transgeneintroduced through genetic engineering techniques.

In another aspect, the present invention provides regenerable cells foruse in tissue culture or inbred corn plant LH185Bt810. The tissueculture will preferably be capable of regenerating plants having thephysiological and morphological characteristics of the foregoing inbredcorn plant, and of regenerating plants having substantially the samegenotype as the foregoing inbred corn plant. Preferably, the regenerablecells in such tissue cultures will be embryos, protoplasts, meristematiccells, callus, pollen, leaves, anthers, roots, root tips, silk, flowers,kernels, ears, cobs, husks or stalks. Still further, the presentinvention provides corn plants regenerated from the tissue cultures ofthe invention.

DEFINITIONS

In the description and tables which follow, a number of terms are used.In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided:

Predicted RM. This trait for a hybrid, predicted relative maturity (RM),is based on the harvest moisture of the grain. The relative maturityrating is based on a known set of checks and utilizes conventionalmaturity systems such as the Minnesota Relative Maturity Rating System.

MN RM. This represents the Minnesota Relative Maturity Rating (MN RM)for the hybrid and is based on the harvest moisture of the grainrelative to a standard set of checks of previously determined MN RMrating. Regression analysis is used to compute this rating.

Yield (Bushels/Acre). The yield in bushels/acre is the actual yield ofthe grain at harvest adjusted to 15.5% moisture.

Moisture. The moisture is the actual percentage moisture of the grain atharvest.

GDU Silk. The GDU silk (=heat unit silk) is the number of growing degreeunits (GDU) or heat units required for an inbred line or hybrid to reachsilk emergence from the time of planting. Growing degree units arecalculated by the Barger Method, where the heat units for a 24-hourperiod are: ${GDU} = {\frac{\left( {{Max}.{+ {Min}}} \right)}{2} - 50.}$

The highest maximum used is 86° F. and the lowest minimum used is 50° F.For each hybrid, it takes a certain number of GDUs to reach variousstages of plant development. GDUs are a way of measuring plant maturity.

Stalk Lodging. This is the percentage of plants that stalk lodge, i.e.,stalk breakage, as measured by either natural lodging or pushing thestalks determining the percentage of plants that break off below theear. This is a relative rating of a hybrid to other hybrids forstandability.

Root Lodging. The root lodging is the percentage of plants that rootlodge; i.e., those that lean from the vertical axis at an approximate30° angle or greater would be counted as root lodged.

Plant Height. This is a measure of the height of the hybrid from theground to the tip of the tassel, and is measured in centimeters.

Ear Height. The ear height is a measure from the ground to the ear nodeattachment, and is measured in centimeters.

Dropped Ears. This is a measure of the number of dropped ears per plot,and represents the percentage of plants that dropped an ear prior toharvest.

Allele. The allele is any of one or more alternative forms of a gene,all of which alleles relate to one trait or characteristic. In a diploidcell or organism, the two alleles of a given gene occupy correspondingloci on a pair of homologous chromosomes.

Backcrossing. Backcrossing is a process in which a breeder repeatedlycrosses hybrid progeny back to one of the parents, for example, a firstgeneration hybrid F₁ with one of the parental genotypes of the F₁hybrid.

Essentially all the physiological and morphological characteristics. Aplant having essentially all the physiological and morphologicalcharacteristics means a plant having the physiological and morphologicalcharacteristics, except for the characteristics derived from theconverted gene.

Quantitative Trait Loci (QTL). Quantitative trait loci (QTL) refer togenetic loci that control to some degree numerically representabletraits that are usually continuously distributed.

Regeneration. Regeneration refers to the development of a plant fromtissue culture.

Single Gene Converted. Single gene converted or conversion plant refersto plants which are developed by a plant breeding technique calledbackcrossing wherein essentially all of the desired morphological andphysiological characteristics of an inbred are recovered in addition tothe single gene transferred into the inbred via the backcrossingtechnique or via genetic engineering.

DETAILED DESCRIPTION OF THE INVENTION

Inbred corn line LH185Bt810is a yellow dent corn with superiorcharacteristics, and provides an excellent parental line in crosses forproducing first generation (F₁) hybrid corn.

LH185Bt810 was developed by using a Holden's third party licenseepartially converted line containing the Bt gene at the BC₂ stage as thenon-recurrent parent to backcross the Bt gene into the LH185 geneticbackground. Molecular marker assays were used to select individualplants for advancement. Ear rows homozygous for the Bt810 trait weresampled for molecular marker evaluation. Utilizing the marker andphenotype comparison to the recurrent parent, individual families wereselected and advanced.

Yield, stalk quality, root quality, disease tolerance, late plantgreenness, late plant intactness, ear retention, pollen sheddingability, silking ability and corn borer tolerance were the criteria usedto determine the rows from which ears were selected.

Inbred corn line LH185Bt810has the following morphologic and othercharacteristics (based primarily on data collected at Williamsburg,Iowa).

VARIETY DESCRIPTION INFORMATION

1. TYPE: Dent

2. REGION WHERE DEVELOPED: Northcentral U.S.

3. MATURITY:

Days Heat Units From emergence to 50% of plants in silk: 83 1679 Fromemergence to 50% of plants in pollen 82 1659${{Heat}\quad {Units}}:={\frac{\begin{matrix}\left\lbrack {{{Max}.\quad {Temp}.\quad \left( {\leqq {86{^\circ}\quad {F.}}} \right)} +} \right. \\\left. {{Min}.\quad {Temp}.\quad \left( {\geqq {50{^\circ}\quad {F.}}} \right)} \right\rbrack\end{matrix}}{2} - 50}$

4. PLANT:

Plant Height (to tassel tip): 189.3 cm (SD=13.39)

Ear Height (to base of top ear): 81.3 cm (6.76)

Average Length of Top Ear Internode: 10.4 cm (1.26)

Average number of Tillers: 0 (0)

Average Number of Ears per Stalk: 1.0 (0.0)

Anthocyanin of Brace Roots: Absent

5. LEAF:

Width of Ear Node Leaf: 9.3 cm (0.83)

Length of Ear Node Leaf: 74.5 cm (3.47)

Number of leaves above top ear: 6 (0.66)

Leaf Angle from 2nd Leaf above ear at anthesis to Stalk above leaf: 42°(15.40)

Leaf Color: Medium Green—Munsell Code 5 GY 4/4

Leaf Sheath Pubescence (Rate on scale from 1=none to 9=like peach fuzz):1

Marginal Waves (Rate on scale from 1=none to 9=many): 3

Longitudinal Creases (Rate on scale from 1=none to 9=many): 3

6. TASSEL:

Number of Lateral Branches: 10 (1.45)

Branch Angle from Central Spike: 42° (12.48)

Tassel Length (from top leaf collar to tassel top): 33.3 cm (4.37)

Pollen Shed (Rate on scale from 0=male sterile to 9=heavy shed): 7

Anther Color: Yellow—Munsell Code 2.5GY 8/8

Glume Color: Medium green—Munsell Code 5GY 6/4

Bar Glumes: Absent

7a. EAR: (Unhusked Data)

Silk Color (3 days after emergency): Light green—Munsell Code 2.5GY 8/4

Fresh Husk Color (25 days after 50% silking): Light green—Munsell Code2.5GY 7/8

Dry Husk Color (65 days after 50% silking): Buff—Munsell Code 7.5YR 7/4

Position of Ear: Upright

Husk Tightness (Rate on scale from 1=very loose to 9=very tight): 5

Husk Extension: Medium (<8 cm)

7b. EAR: (Husked Ear Data)

Ear Length: 15.2 cm (1.59)

Ear Diameter at mid-point: 42.9 mm (2.60)

Ear Weight: 102.0 gm (24.14)

Number of Kernel Rows: 12 (1.07)

Kernel Rows: Distinct

Row Alignment: Straight

Shank Length: 6.4 cm (1.30)

Ear Taper: Slight

8. KERNEL: (Dried)

Kernel Length: 11.8 mm (0.5)

Kernel Width: 10.0 mm (0.5)

Kernel Thickness: 5.1 mm (0.6)

Round Kernels (Shape Grade): 44.0% (1.50)

Aleurone Color Pattern: Homozygous

Aleurone Color: White—Munsell Code 2.5Y 8/2

Hard Endosperm Color: Yellow—Munsell Code 2.5Y 8/10

Endosperm Type: Normal Starch

Weight per 100 kernels: 36.2 gm (1.10)

9. COB:

Cob Diameter at Mid-Point: 30.1 mm (1.70)

Cob Color: White—Munsell code 2.5Y 8/2

10. AGRONOMIC TRAITS:

5 Stay Green (at 65 days after anthesis) (Rate on scale from 1=worstto9=excellent)

0% Dropped Ears (at 65 days after anthesis)

0% Pre-anthesis Brittle Snapping

0% Pre-anthesis Root Lodging

0% Post-anthesis Root Lodging (at 65 days after anthesis)

This invention is also directed to methods for producing a corn plant bycrossing a first parent corn plant with a second parent corn plant,wherein the first or second corn plant is the inbred corn plant from theline LH185Bt810. Further, both first and second parent corn plants maybe from the inbred line LH185Bt810. Therefore, any methods using theinbred corn line LH185Bt810 are part of this invention: selfing,backcrosses, hybrid breeding, and crosses to populations. Any plantsproduced using inbred corn line LH185Bt810 as a parent are within thescope of this invention. Advantageously, the inbred corn line is used incrosses with other corn varieties to produce first generation (F₁) cornhybrid seed and plants with superior characteristics.

As used herein, the term “plant” includes plant cells, plantprotoplasts, plant cell of tissue culture from which corn plants can beregenerated, plant calli, plant clumps, and plant cells that are intactin plants or parts of plants, such as pollen, flowers, kernels, ears,cobs, leaves, husks, stalks, and the like.

The present invention contemplates a corn plant regenerated from atissue culture of an inbred (e.g., LH185Bt810) or hybrid plant of thepresent invention. As is well known in the art, tissue culture of corncan be used for the in vitro regeneration of a corn plant. By way ofexample, a process of tissue culturing and regeneration of corn isdescribed in European Patent Application, publication 160,390, thedisclosure of which is incorporated by reference. Corn tissue cultureprocedures are also described in Green & Rhodes (1982) and Duncan, etal., (1985). The study by Duncan et al., (1985) indicates that 97percent of cultured plants produced calli capable of regeneratingplants. Subsequent studies have shown that both inbreds and hybridsproduced 91 percent regenerable calli that produced plants.

Other studies indicate that non-traditional tissues are capable ofproducing somatic embryogenesis and plant regeneration. See, e.g.,Songstad et al., (1988); Rao et al., (1986); and Conger et al., (1987),the disclosures of which are incorporated herein by reference.Regenerable cultures may be initiated from immature embryos as describedin PCT publication WO 95/06128, the disclosure of which is incorporatedherein by reference.

Thus, another aspect of this invention is to provide for cells whichupon growth and differentiation produce the inbred line LH185Bt810.

LH185Bt810is similar to LH185, however, there are numerous differencesincluding the ear height. LH185Bt810is taller in ear height (81.3 cm vs47.5 cm) than Lh185. LH185Bt810 is also taller in plant height (189.3 cmvs. 174.4 cm) than LH185. Additionally LH185Bt810is lighter green inplant color than LH185. When using the Munsell Color Charts for PlantTissues as a reference, LH185Bt810 would be classified as 5GY 4/4 andLH185 would be classified as 7.5GY 3/4.

Some of the criteria used to select ears in various generations include:yield, stalk quality, root quality, disease tolerance, late plantgreenness, late season plant intactness, ear retention, pollen sheddingability, silking ability, and corn borer tolerance. During thedevelopment of the line, crosses were made to inbred testers for thepurpose of estimating the line's general and specific combining ability,and evaluations were run by the Williamsburg, Iowa Research Station. Theinbred was evaluated further as a line and in numerous crosses by theWilliamsburg and other research stations across the Corn Belt. Theinbred has proven to have a very good combining ability in hybridcombinations.

The inbred has shown uniformity and stability. It has beenself-pollinated and ear-rowed a sufficient number of generations, withcareful attention to uniformity of plant type to ensure homozygosity andphenotypic stability. The line has been increased both by hand andsibbed in isolated fields with continued observations for uniformity. Novariant traits have been observed or are expected in LH185Bt810.

TABLES

In the tables that follow, the traits and characteristics of inbred cornline LH185Bt810 are given in hybrid combination. The data collected oninbred corn line LH185Bt810 is presented for the key characteristics andtraits. The tables present yield test information about LH185Bt810.LH185Bt810was tested in several hybrid combinations at numerouslocations, with two or three replications per location. Informationabout these hybrids, as compared to several check hybrids, is presented.

The first pedigree listed in the comparison group is the hybridcontaining LH185Bt810. Information for the pedigree includes:

1. Mean yield of the hybrid across all locations.

2. A mean for the percentage moisture (% M) for the hybrid across alllocations.

3. A mean of the yield divided by the percentage moisture (Y/M) for thehybrid across all locations.

4. A mean of the percentage of plants with stalk lodging (% Stalk)across all locations.

5. A mean of the percentage of plants with root lodging (% Root) acrossall locations.

6. A mean of the percentage of plants with dropped ears (% Drop).

7. The number of locations indicates the locations where these hybridswere tested together.

The series of hybrids listed under the hybrid containing LH185Bt810 areconsidered check hybrids. The check hybrids are compared to hybridscontaining the inbred LH185Bt810.

The (+) or (−) sign in front of each number in each of the columnsindicates how the mean values across plots of the hybrid containinginbred LH185Bt810 compare to the check crosses. A (+) or (−) sign infront of the number indicates that the mean of the hybrid containinginbred LH185Bt810 was greater or lesser, respectively, than the mean ofthe check hybrid. For example, a +4 in yield signifies that the hybridcontaining inbred LH185Bt810produced 4 bushels more corn than the checkhybrid. If the value of the stalks has a (−) in front of the number 2,for example, then the hybrid containing the inbred LH185Bt810 had 2%less stalk lodging than the check hybrid.

TABLE 1 OVERALL COMPARISONS LH185Bt810 × HC33 HYBRID VERSUS CHECKHYBRIDS Mean % % % Pedigree Yield % M Y/M Stalk Root Drop HC33 ×LH185Bt810 212 17.50 12.38 2 9 0 HC33 × LH185 203 16.80 12.37 1 3 0Difference 9 0.7 0.01 1 6 0 Locations 13 13 13 13 12 12 HC33 ×LH185Bt810 212 17.50 12.38 2 9 0 34R06 Pioneer Brand 206 17.30 12.10 2 40 Difference 6 0.3 0.28 0 5 0 Locations 13 13 13 13 12 12 HC33 ×LH185Bt810 212 17.30 12.50 2 10 0 N6800Bt Northrup King 194 17.80 11.110 16 0 Difference 18 −0.4 1.39 2 −6 0 Locations 12 12 12 12 11 11

TABLE 2 OVERALL COMPARISONS LH185Bt810 × LH198 HYBRID VERSUS CHECKHYBRIDS Mean % % % Pedigree Yield % M Y/M Stalk Root Drop LH185Bt810 ×LH198 200 18.40 11.20 2 11 0 LH185 × LH198 196 17.70 11.42 1 7 0Difference 4 −0.8 0.82 −8 25 0 Locations 50 50 50 48 46 37 LH185Bt810 ×0LH198 207 1640 1272 0 26 0 33A14 Pioneer Brand 203 17.20 11.90 8 1 0Difference 4 −0.80 0.82 −8 25 0 Locations 5 5 5 5 5 5 LH185Bt810 × LH198201 17.70 11.63 3 14 0 34R06 Pioneer Brand 197 17.50 11.40 2 8 0Difference 4 0.10 0.19 1 6 0 Locations 31 31 31 30 29 24

TABLE 3 OVERALL COMPARISONS LH185Bt810 × LH200 HYBRID VERSUS CHECKHYBRIDS Mean % % % Pedigree Yield % M Y/M Stalk Root Drop LH185Bt810 ×LH200 198 20.00 10.41 2 12 0 LH185 × LH200 196 19.00 10.78 1 6 0Difference 2 1.10 −0.37 1 6 0 Locations 24 24 24 23 22 18

TABLE 4 OVERALL COMPARISONS LH185Bt810 × LH235 HYBRID VERSUS CHECKHYBRIDS Mean % % % Pedigree Yield % M Y/M Stalk Root Drop LH185Bt810 ×LH235 198 20.00 10.33 4 13 0 LH185 × LH235 199 19.30 10.71 2 10 0Difference −1 0.60 −0.38 2 3 0 Locations 39 39 39 37 35 31 LH185Bt810 ×LH235 207 18.80 11.43 5 13 0 33A14 Pioneer Brand 199 18.20 11.31 6 2 0Difference 8 0.70 0.12 −1 11 0 Locations 22 22 22 21 20 20

TABLE 5 OVERALL COMPARISONS LH185Bt810 × LH242 HYBRID VERSUS CHECKHYBRIDS Mean % % % Pedigree Yield % M Y/M Stalk Root Drop LH185Bt810 ×LH242 201 18.70 11.21 3 9 0 LH185 × LH242 195 18.00 11.27 2 4 0Difference 6 0.70 −0.06 1 5 0 Locations 45 45 45 42 40 31 LH185Bt810 ×LH242 207 18.00 11.81 5 11 0 34R06 Pioneer Brand 198 17.50 11.46 2 6 0Difference 9 0.50 0.35 3 5 0 Locations 27 27 27 26 25 20

When the term inbred corn plant is used in the context of the presentinvention, this also includes any single gene conversions of thatinbred. The term single gene converted plant as used herein refers tothose corn plants which are developed by a plant breeding techniquecalled backcrossing wherein essentially all of the desired morphologicaland physiological characteristics of an inbred are recovered in additionto the single gene transferred into the inbred via the backcrossingtechnique. Backcrossing methods can be used with the present inventionto improve or introduce a characteristic into the inbred. The termbackcrossing as used herein refers to the repeated crossing of a hybridprogeny back to one of the parental corn plants for that inbred. Theparental corn plant which contributes the gene for the desiredcharacteristic is termed the nonrecurrent or donor parent. Thisterminology refers to the fact that the nonrecurrent parent is used onetime in the backcross protocol and therefore does not recur. Theparental corn plant to which the gene or genes from the nonrecurrentparent are transferred is known as the recurrent parent as it is usedfor several rounds in the backcrossing protocol (Poehlman & Sleper,1994; Fehr, 1987). In a typical backcross protocol, the original inbredof interest (recurrent parent) is crossed to a second inbred(nonrecurrent parent) that carries the single gene of interest to betransferred. The resulting progeny from this cross are then crossedagain to the recurrent parent and the process is repeated until a cornplant is obtained wherein essentially all of the desired morphologicaland physiological characteristics of the recurrent parent are recoveredin the converted plant, in addition to the single transferred gene fromthe nonrecurrent parent.

The selection of a suitable recurrent parent is an important step for asuccessful backcrossing procedure. The goal of a backcross protocol isto alter or substitute a single trait or characteristic in the originalinbred. To accomplish this, a single gene of the recurrent inbred ismodified or substituted with the desired gene from the nonrecurrentparent, while retaining essentially all of the rest of the desiredgenetic, and therefore the desired physiological and morphological,constitution of the original inbred. The choice of the particularnonrecurrent parent will depend on the purpose of the backcross, one ofthe major purposes is to add some commercially desirable, agronomicallyimportant trait to the plant. The exact backcrossing protocol willdepend on the characteristic or trait being altered to determine anappropriate testing protocol. Although backcrossing methods aresimplified when the characteristic being transferred is a dominantallele, a recessive allele may also be transferred. In this instance itmay be necessary to introduce a test of the progeny to determine if thedesired characteristic has been successfully transferred.

Many single gene traits have been identified that are not regularlyselected for in the development of a new inbred but that can be improvedby backcrossing techniques. Single gene traits may or may not betransgenic, examples of these traits include but are not limited to,male sterility, waxy starch, herbicide resistance, resistance forbacterial, fungal, or viral disease, insect resistance, male fertility,enhanced nutritional quality, industrial usage, yield stability andyield enhancement. These genes are generally inherited through thenucleus. Some known exceptions to this are the genes for male sterility,some of which are inherited cytoplasmically, but still act as singlegene traits. Several of these single gene traits are described in U.S.Pat. No. 5,777,196, the disclosure of which is specifically herebyincorporated by reference.

A further aspect of the invention relates to tissue culture of cornplants designated LH185Bt810. As used herein, the term “tissue culture”indicates a composition comprising isolated cells of the same or adifferent type or a collection of such cells organized into parts of aplant. Exemplary types of tissue cultures are protoplasts, calli, plantclumps, and plant cells that can generate tissue culture that are intactin plants or parts of plants, such as embryos, pollen, flowers, kernels,ears, cobs, leaves, husks, stalks, roots, root tips, anthers, silk andthe like. In a preferred embodiment, tissue culture is embryos,protoplast, meristematic cells, pollen, leaves or anthers. Means forpreparing and maintaining plant tissue culture are well known in theart. By way of example, a tissue culture comprising organs such astassels or anthers, has been used to produce regenerated plants. (SeeU.S. Pat. No. 5,445,961 and U.S. Pat. No. 5,322,789, the disclosures ofwhich are incorporated herein by reference).

DEPOSIT INFORMATION

Inbred seeds of LH185Bt810 have been placed on deposit with the AmericanType Culture Collection (ATCC), Manassas, Va., under Deposit AccessionNumber PTA-167 on Jun. 3, 1999. A Plant Variety Protection Certificateis being applied for with the United States Department of Agriculture.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity andunderstanding, it will be obvious that certain changes and modificationsmay be practiced within the scope of the invention, as limited only bythe scope of the appended claims.

What is claimed is:
 1. An inbred corn seed designated LH185Bt810, wherein a sample of said seed has been deposited under ATCC Accession No. PTA-167.
 2. A corn plant, or its parts, produced by growing the seed of claim
 1. 3. Pollen of the plant of claim
 2. 4. An ovule of the plant of claim
 2. 5. A corn plant having all of the physiological and morphological characteristics of the corn plant of claim 2, or its parts.
 6. Tissue culture of the seed of claim
 1. 7. A corn plant regenerated from the tissue culture of claim 6, wherein said corn plant is capable of expressing all the physiological and morphological characteristics of inbred corn line LH185Bt810.
 8. Tissue culture of regenerable cells of the plant, or its parts, of claim
 2. 9. The tissue culture of claim 8, wherein the regenerable cells are from embryos, meristematic cells, pollen, leaves, anthers, roots, root tips, silk, flower, kernels, ears, cobs, husks, stalks, protoplasts derived therefrom or calli derived therefrom.
 10. A corn plant regenerated from the tissue culture of claim 9, wherein said corn plant is capable of expressing all the physiological and morphological characteristics of inbred corn line LH185Bt810.
 11. A method for producing a hybrid corn seed comprising crossing a first inbred parent corn plant with a second inbred parent corn plant and harvesting the resultant hybrid corn seed, wherein said first or second parent corn plant is the corn plant of claim
 2. 12. A hybrid corn seed produced by the method of claim
 11. 13. A hybrid corn plant, or its parts, produced by growing said hybrid corn seed of claim
 12. 14. Corn seed produced by growing said hybrid corn plant of claim
 13. 15. A corn plant, or its parts, produced from seed of claim
 14. 16. A method for producing a hybrid corn seed comprising crossing an inbred plant according to claim 2 with another, different corn plant.
 17. A hybrid corn seed produced by the method of claim
 16. 18. A hybrid corn plant, or its parts, produced by growing said hybrid corn seed of claim
 17. 19. Corn seed produced from said hybrid corn plant of claim
 18. 20. A corn plant, or its parts, produced from the corn seed of claim
 19. 21. The corn plant of claim 5, further comprising a single gene conversion.
 22. The corn plant of claim 21, further comprising a cytoplasmic factor conferring male sterility.
 23. The single gene conversion of the corn plant of claim 21, where the gene is a gene which is introduced by transgenic methods.
 24. The single gene conversion of the corn plant of claim 21, where the gene is a dominant allele.
 25. The single gene conversion of the corn plant of claim 21, wherein the gene is a recessive allele.
 26. The single gene conversion corn plant of claim 21, where the gene confers herbicide resistance.
 27. The single gene conversion of the corn plant of claim 21, where the gene confers insect resistance.
 28. The single gene conversion of the corn plant of claim 21, where the gene confers resistance to bacterial, fungal, or viral disease.
 29. The single gene conversion of the corn plant of claim 21, where the gene confers male sterility.
 30. The single gene conversion of the corn plant of claim 21, where the gene confers waxy starch. 